The AC133 antigen is selectively expressed on subset of CD 34+ cells
isolated from leukapheresis products from high risk breast cancer patients receiving
chemotherapy plus G-CSF. MiniMACS AC133+ isolated cells contained a mean
of 85% (80-90) AC133+ cells. Enriched AC133+ cells coexpressed 80%
CD34+, 6.6% CD33+ and 2% CD15+. Separated AC133+
cells contained 600 GFU-GM/104 cells and 70 BFU-E/104 cells.
Flow-cytometric analysis indicated that AC133+ cells were isolated from cells
population with low granularity (SS), while CD33+ a CD15+ cells
had a high granularity. After a seven-day ex vivo expansion in the presence of
SCF + IL-3 + IL11, the expansion of cells increased 19.4 times. The mean
percentage of blasts decreased from 100% at the start of culture to 81% on day 3 and
30% on day 7. Promyelocytes were slow to appear with 10% present on day 3, but thereafter
increased to 33% on day 7. The appearance of myelocytes and metamyelocytes lagged
3 days behind promyelocytes and continued to increase during culture to become the
predominant (30%) cell type on day 7. Very few neutrophils (2%) were observed in any of
the cultures on day 7. Monocytes or macrophages were not detected on day 7. By day
7 megakaryocytes were present at low levels (10%). The mean value of CFU-GM in the
culture after day 7 of ex vivo expansion in the presence of SCF+IL-3+IL-11 had
increased 45-fold, BFU-E 5-fold. After 7 days of expansion with IL-3+SCF+IL-11 cells
expressed a mean of 12% CD34+, 8% AC133+, 59% CD33+
and 30% CD15+. The aim of this experiment was to determine whether ex vivo
culture of peripheral blood AC133+ cells could generate sufficient numbers of
progenitors to potentially abrogate cytopenia after transplantation and passive purging of
tumor cells.

Effect of vanadium on hepatic xenobiotic biotransformation in rats exposed to
diethylnitrosamine (DENA, 200 mg/kg body weight, intraperitoneally) was investigated to
elucidate a possible mechanism of vanadium mediated prevention of chemical
carcinogenesis. Vanadium supplementation (0.5 ppm ad libitum with drinking water),
at different phases before and after DENA treatment, significantly modulated the decrease
in contents of total cytochrome P-450, cytochrome b5, activity of nicotinamide
adenine dinucleotide phosphate (NADPH), (reduced form) cytochrome reductase, and uridine
diphospho-glucuronyl transferase (UDPGT) in microsomal fractions of whole liver,
hyperplastic nodules (HNs) and non nodular surrounding parenchyma (NNSP) as induced by
DENA, 20 weeks following its administration. Supplementary vanadium had also substantial
influence on the activities of cytosolic enzymes, like, uridine diphospho (UDP)-glucose
dehydrogenase and NAD(P)H: quinone oxidoreductase (DT-diaphorase) in the concerned tissue
which were observed to be remarkably decreased as a result of DENA treatment in
comparison to that of the control counterparts. However, vanadium was found to have little
or no effect on the lowering of aryl hydrocarbon hydroxylase (AHH) activity by DENA
administration. On the basis of significant modulation of DENA induced alterations in
cytosolic and microsomal enzyme activity it can be presumed that the chemoprotective
effect of vanadium might be mediated through elevation of phase II conjugating enzymes
which in turn, lead to a move and shift of metabolic profile that reduces the
intracellular concentration of carcinogen derived reactive intermediates.

It has been observed that the progressive ascitic growth of a transplantable
T-cell lymphoma of spontaneous origin in murine host, designated as Dalton’s lymphoma
(DL), induces inhibition of various immune responses and is associated with an involution
of thymus accompanied by a massive depletion of the cortical region and alteration in
the distribution of thymocytes caused by induction of apoptosis with a decrease of
CD4+CD8+, CD4+CD8- and CD4-CD8+
thymocytes. Here, we report that serum of DL-bearing mice contains soluble factors capable
of inducing thymocyte apoptosis, the effectiveness of which increases with the progression
of tumor growth. A decline of essential cytokines and hormones in the body due to
their depletion by DL cells, which being a T-cell phenotype may have similar growth
factor requirements, is ruled out by our results, suggesting additional apoptosis-inducing
factors to be present in the tumor serum. Partial characterization of the serum to
identify the biochemical nature of the putative serum-borne apoptosis inducing factor(s)
showed that the same was proteinaceous. Further analysis of the sera of normal and
DL-bearing mice by gel filtration using fast protein liquid chromatography (FPLC) and by
sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) revealed that protein
profile in the two sera differed quantitatively as well as qualitatively. FPLC analysis
could resolve six peaks in both the sera, out of which the peak containing protein(s) in
the range of MW 35 kD showed a higher magnitude and apoptotic activity followed by
peaks containing proteins of MW in the range of 67 and 116 kD respectively as compared to
that of the corresponding peaks in the normal serum. These observations were also
confirmed by SDS-PAGE, with the resolution of additional proteins in the range of 25-26 kD
which were found to be absent in normal serum. Further, the paper discusses different
possible factors that could be associated with the progression of DL growth.

Dipeptidyl peptidase IV is known to be involved, due to both hydrolytic and
non-hydrolytic mechanisms, in various cell functions of normal and cancer cells as well.
In this report dipeptidyl peptidase IV substrate and pH preferences, some inhibition
parameters, freezing/thawing sensitivity and stability against hydrolysis by trypsin were
studied in C6 rat glioma cells. Our results confirmed substantial heterogeneity of
dipeptidyl peptidase IV population. Such observation is important to avoid methodological
artifacts and to decrease risk of misinterpretations in biological studies.

L1210/VCR-1 and L1210/VCR-2 cell lines are multidrug resistant (MDR) sublines obtained
by adaptation of mouse leukemic cell line L1210 to vincristine and, the development of MDR
in these cell lines has been found to be associated with an overexpression of
P-glycoprotein (PGP). In the present work we studied the relationship between the
structure of 15 cytotoxic active substances (drugs) and their cytotoxicities on
L1210/VCR-1 and L1210/VCR-2 resistant cell lines. The resistance of these MDR cells to the
respective drugs was expressed as the ratio of IC50 values obtained for
resistant and sensitive cells. These values of resistance were correlated with the
following physico-chemical constants of the test substances: binding energy, Ebind;
total energy of the molecule, Esum; aromaticity, Kpi; molecular
weight, Mw; acidobasic constant, pKa; partition coefficient in
water/octanol two phase system, log(p). It has been found that according to the cytotoxic
effects the tested drugs may be divided into three groups: (i) drugs with higher
cytotoxicity to the resistant cell lines as to sensitive cells (collateral
hypersensitivity); (ii) drugs exhibiting approximately similar effects on sensitive and
resistant cell lines; (iii) drugs with weaker cytotoxicity to resistant cells than to
sensitive cells. No direct correlations with any physico-chemical constant described above
could be established for cell resistance to the drug studied. However, resistance values
could be fitted by multiple exponential regression with all described physico-chemical
constants implied as six independent variables. The latter procedure made us to conclude
that the ability of a drug to be a substrate for PGP is connected with its
fulfilling the following criteria: (i) flexible structure of its molecule; (ii) molecular
weight lower than ~1300 g/mol; (iii) nonprotonized character at pH 7.0.

Epidermal growth factor receptor (EGF-R) is known as an indicator of endocrine
independence of breast cancer. However, a small proportion of EGF-R expressing tumors
was found to respond to endocrine treatments. On the other side, a cut-off point of
EGF-R positivity is not yet defined. In the aim to find out whether there exists
a cut-off value that sharply discriminate the endocrine sensitive and endocrine
insensitive breast cancers, the quantitative EGF-R content was analyzed in a group of
42 female patients with metastatic disease, being routinely treated with chemo-,
chemo-endocrine, or endocrine therapy alone. Steroid receptors (SR) and EGF-R were
determined by biochemical methods in tissue samples of an unselected group of patients.
Patients with metastatic disease, either at diagnosis, or developed after the treatment of
operable or locally advanced breast cancer, were included in the present analysis.
According to the treatments used, and their therapeutic response, all patients were
divided in endocrine sensitive or resistant, and chemo-sensitive or resistant. The SR and
EGF-R status and content was analyzed in relation to the sensitivity to both systemic
treatments. The EGF-R content was significantly lower in responders to endocrine
treatments, compared to non-responders, while there was no difference in EGF-R level, in
relation to the sensitivity to chemotherapy. In addition, the EGF-R content was
significantly higher in chemo-sensitive tumors, than in endocrine sensitive. On the
contrary, ER content was significantly higher in endocrine sensitive, than in endocrine
resistant, and in chemo sensitive patients, as well. Similar differences were found in PR
content, but they were less pronounced. While the individual ER contents in endocrine
sensitive and endocrine resistant tumors overlapped, the EGF-R ranges were different: no
one endocrine sensitive tumor exceeded the EGF-R content of 26 fmol/mg, thus suggesting
the EGF-R cut-off point of endocrine sensitivity. The clinical use of EGF-R, with the
cut-off point of 26 fmol/mg, in addition to clinical criteria of endocrine sensitivity and
SRs, would significantly improve the correct endocrine sensitivity prediction (from 52 to
78%). In conclusion, in a group of metastatic breast cancer patients, treated
routinely by systemic therapies it was found, that the use of higher cut-off point for
EGF-R positivity can improve the prediction of endocrine sensitivity. The prognostic
relevance of this cut-off value remains to be analyzed.

This report describes a new case of gamma-1-heavy chain disease found in
a woman with malignant lymphoproliferative disease. The patient’s serum and urine
containing gamma-1-heavy chains were analyzed using different electrophoretic approaches,
especially two-dimensional electrophoresis and immunoblotting analysis. In a serum
sample, five sets of gamma-1-heavy chain spots differing in molecular weight with acidic
pI values and one set of more basic gamma-1-heavy chain spots were found. The major group
of spots exhibited molecular weight in the range from 29 to 39 kDa. Examination of urine
sample proved the presence of the more basic set of gamma-1-heavy chain spots and two
acidic groups, including 29 to 39 kDa set.

The participation of lipid peroxidation products in the mechanisms of paraquat toxicity
in Ehrlich ascites tumor (EAT) cells was observed. Paraquat in a concentration
0.5-1.0 mmol increased the level of lipid peroxidation according to the Ohakawa TBARS
(thiobarbituric acid-reactive substances) method. These changes in TBARS production in EAT
cells correlated with paraquat toxicity on the cells registered by using the method for
cell injury, which is based on changes in lactate dehydrogenase activity. The metal
chelator DTA removed the effect of paraquat on TBARS production and on cell injury. The
present data suggested that the increased level of lipid peroxidation and cell injury is
a result of the paraquat action in EAT cells depending on iron.

Treatment with interferon-alpha (IFNalpha) prolongs survival in chronic myeloid
leukemia (CML). Additionally, cytarabine (AraC) can reduce the number of Ph
+ metaphases.
Fortythree previously untreated patients with CML in chronic phase were randomly assigned
to receive either. IFNalpha 2b (5 MU sqm/daily) or IFNalpha 2b in the same dosages plus
monthly courses of low-dose AraC. The aim were complete hematologic remission at
6 months and cytogenetic response at 12 months.
A complete hematologic remission occurred in 60.4% patients with single IFNalpha 2b in
76.2% patients with combination therapy. A cytogenetic response was present in 13.9%
(major in 2 patients) with IFN therapy and in 38.1% patients with combination
therapy. Two of 21 patients treated with IFNalpha/AraC therapy achieved major (9.52%),
4 partial (19.04%) and 2 minor (9.52%) cytogenetic response. Major side effects
were cytopenia (20.1%), flu-like syndromes (42.4%) and increase of hepatic transaminases
(3.4%). The side effects were more significant in the group receiving combination therapy.
Based on published data that show a survival advantage for patients who achieved any
cytogenetic response, and high rate of cytogenetic response which we observed in our study
we believe that IFN plus AraC regimen could be a front-line therapy for CML.

Radiotherapy and chemotherapy, alone or in combination, are curative treatment
methods in early stages of Hodgkin’s disease (HD). The choice of treatment depends on
the stage of the disease, histological type and localization of the tumor, as well as on
other prognostic factors. A retrospective study was conducted including 145 patients
with clinical Stages I and II of HD according to Ann Arbor classification, all
treated in the Masaryk Memorial Cancer Institute in Brno during the years 1985 through
1994. 80 patients were males (55%) and 65 patients females (45%). The age of the patients
ranged from 11 to 77 years, with an average of 34.8 years. 41 patients were diagnosed with
Stage IA tumor, 1 patient with Stage IB, 75 patients with Stage IIA and 28 with Stage
IIB disease. The histological types of the disease were lymphocyte predominant in 23
patients, nodular sclerosis in 49 patients, mixed cellularity in 65 cases and lymphocyte
depletion in 8 cases.
91 patients were treated with radiotherapy alone. In this group 14 patients relapsed
within the radiation field (15%) and 25 outside the radiation field (28%). 39
patients were treated with combination of radiotherapy and chemotherapy. In this group
relapse occurred within the radiation field in 3 patients (8%) and outside the
radiation field in 7 patients (18%). 15 patients were given chemotherapy alone,
7 patients from this group experienced a relapse.
The five-year survival was 81% in patients with Stages IA and IIA disease, 65% in Stages
IB and IIB disease. The five-year survival in the patients who relapsed was 56%.
Radiotherapy remains the curative method of choice in highly selected group of patients
with early stages of Hodgkin’s disease.
The results of radiotherapy alone are unsatisfactory in unselected clinical Stage I-II
patients because of the presence of patients with adverse prognostic factors, particularly
B symptomatology, mixed cellularity/lymphocyte depletion histology, higher age. These
patients are candidates for combined treatment. Modern equipment and meticulous treatment
are conditions crucial for the outcome of curative radiotherapy in patients with
Hodgkin’s disease.
Combination chemotherapy is very effective in the treatment of relapse following the
primary radiotherapy.

The impact of delivered dose errors on local control of irradiated
advanced laryngeal cancer

On the basis of 1015 entrance and 863 exit dose in vivo measurements, 863
calculations of midline dose were done, and the average deviation and ranges of its value
were estimated. Data of 710 advanced larynx cancers were reviewed in order to achieve
dose-response relationship. Patients data were fitted directly to L-Q model using maximum
likelihood estimation. In 16.5% of measurements the deviation of midline dose was larger
than -5.2%. A steep dose-response relationship for TCP was found. Considering -5.2%
deviation of 2 Gy fraction and 72 Gy of total dose, the 17% (from 48 to 31%) decrease
of TCP was found. It shows that deviations of delivered dose influence the tumor control
probability and that after systematic error finding during fractionated radiotherapy the
value of remaining fraction size and total dose should be modified to compensate the
change of TCP.